/*

 * Copyright 2009-2012 Niels Provos and Nick Mathewson

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. The name of the author may not be used to endorse or promote products

 *    derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "event2/event-config.h"

/* With glibc we need to define this to get PTHREAD_MUTEX_RECURSIVE. */

#define _GNU_SOURCE

#include <pthread.h>

struct event_base;

#include "event2/thread.h"

#include <stdlib.h>

#include <string.h>

#include "mm-internal.h"

#include "evthread-internal.h"

static pthread_mutexattr_t attr_recursive;

static void *

evthread_posix_lock_alloc(unsigned locktype)

{

	pthread_mutexattr_t *attr = NULL;

	pthread_mutex_t *lock = mm_malloc(sizeof(pthread_mutex_t));

	if (!lock)

		return NULL;

	if (locktype & EVTHREAD_LOCKTYPE_RECURSIVE)

		attr = &attr_recursive;

	if (pthread_mutex_init(lock, attr)) {

		mm_free(lock);

		return NULL;

	}

	return lock;

}

static void

evthread_posix_lock_free(void *_lock, unsigned locktype)

{

	pthread_mutex_t *lock = _lock;

	pthread_mutex_destroy(lock);

	mm_free(lock);

}

static int

evthread_posix_lock(unsigned mode, void *_lock)

{

	pthread_mutex_t *lock = _lock;

	if (mode & EVTHREAD_TRY)

		return pthread_mutex_trylock(lock);

	else

		return pthread_mutex_lock(lock);

}

static int

evthread_posix_unlock(unsigned mode, void *_lock)

{

	pthread_mutex_t *lock = _lock;

	return pthread_mutex_unlock(lock);

}

static unsigned long

evthread_posix_get_id(void)

{

	union {

		pthread_t thr;

#if _EVENT_SIZEOF_PTHREAD_T > _EVENT_SIZEOF_LONG

		ev_uint64_t id;

#else

		unsigned long id;

#endif

	} r;

#if _EVENT_SIZEOF_PTHREAD_T < _EVENT_SIZEOF_LONG

	memset(&r, 0, sizeof(r));

#endif

	r.thr = pthread_self();

	return (unsigned long)r.id;

}

static void *

evthread_posix_cond_alloc(unsigned condflags)

{

	pthread_cond_t *cond = mm_malloc(sizeof(pthread_cond_t));

	if (!cond)

		return NULL;

	if (pthread_cond_init(cond, NULL)) {

		mm_free(cond);

		return NULL;

	}

	return cond;

}

static void

evthread_posix_cond_free(void *_cond)

{

	pthread_cond_t *cond = _cond;

	pthread_cond_destroy(cond);

	mm_free(cond);

}

static int

evthread_posix_cond_signal(void *_cond, int broadcast)

{

	pthread_cond_t *cond = _cond;

	int r;

	if (broadcast)

		r = pthread_cond_broadcast(cond);

	else

		r = pthread_cond_signal(cond);

	return r ? -1 : 0;

}

static int

evthread_posix_cond_wait(void *_cond, void *_lock, const struct timeval *tv)

{

	int r;

	pthread_cond_t *cond = _cond;

	pthread_mutex_t *lock = _lock;

	if (tv) {

		struct timeval now, abstime;

		struct timespec ts;

		evutil_gettimeofday(&now, NULL);

		evutil_timeradd(&now, tv, &abstime);

		ts.tv_sec = abstime.tv_sec;

		ts.tv_nsec = abstime.tv_usec*1000;

		r = pthread_cond_timedwait(cond, lock, &ts);

		if (r == ETIMEDOUT)

			return 1;

		else if (r)

			return -1;

		else

			return 0;

	} else {

		r = pthread_cond_wait(cond, lock);

		return r ? -1 : 0;

	}

}

int

evthread_use_pthreads(void)

{

	struct evthread_lock_callbacks cbs = {

		EVTHREAD_LOCK_API_VERSION,

		EVTHREAD_LOCKTYPE_RECURSIVE,

		evthread_posix_lock_alloc,

		evthread_posix_lock_free,

		evthread_posix_lock,

		evthread_posix_unlock

	};

	struct evthread_condition_callbacks cond_cbs = {

		EVTHREAD_CONDITION_API_VERSION,

		evthread_posix_cond_alloc,

		evthread_posix_cond_free,

		evthread_posix_cond_signal,

		evthread_posix_cond_wait

	};

	/* Set ourselves up to get recursive locks. */

	if (pthread_mutexattr_init(&attr_recursive))

		return -1;

	if (pthread_mutexattr_settype(&attr_recursive, PTHREAD_MUTEX_RECURSIVE))

		return -1;

	evthread_set_lock_callbacks(&cbs);

	evthread_set_condition_callbacks(&cond_cbs);

	evthread_set_id_callback(evthread_posix_get_id);

	return 0;

}